Sadiron



April 22 1924.

J. A. SPENCER SADIRON Filed June 29 1922 2 She ets-Sh eet 1 III/IIIIl/I/ M m a I 1 I April 22, 1924. 1,491,363-

- J. A. SPENCER SADIRON v Filed June 29. 1922 2 Sheets-Sheet 2 [nu 12223" my I Q -rr Patented Apr. 22 1924.

UN TED STATES PATENT OFFICE.

JOHN A. SPENCER, OI REVERE, MASSACHUSETTS, AS SIGNOR TO SPENCER THERMO- S'I'A'l COMPANY, 01' CAMBRIDGE, MASSACHUSETTS, A CORPORATION OF MASSA- SADIRON.

Application filed June 29,

' use the same.

The present invention relates to sadirons and more particularly to sadirons of an imroved type in which apparatus is embodied or automatically regulating the temperature.

It is the object of the present invention to improve the construction and operation of apparatus of this type in such a manner 2 that intimate and automatic control of the temperature may be obtained without undul com licating the structure of the iron. ith t is object in view the features of the invention consist in certain novel features of construction, combinations and arrangements of parts hereinafter described and claimed, the advantages of which will be obvious to thoseiskille in the art from the following description:

In the accompanying drawings illustrating the preferred form of the invention, Fig. 1 represents a plan view of the base portion of a sadiron embodyin the features of the invention, together wit the associated heating element and thermostatic control; Fig. 2 is a plan view of the base with the heating element and thermostatic control removed therefrom; Fig. 3 is a section in elevation of the base member shown in Fig. 2;

and Fig. 4 represents a section in elevation of an entire sadiron assembly embodying the invention.

The illustrated embodiment of the invention shows a sadiron having a metallic base member provided with a 'ointed end 11 of the usual form. 'Supporte on top of the base member is a heati element indicated generally at 12 and consisting of a spiral of at resistance wire 14 woun upon a strip of mica 16 or similar material. As indicated in Fig. 1, the heating element 'com-' prisesessentially two strips of insulatin material with the resistance wire woun thereon connected at theirforward ends to HEISSUED form substantially a triangle. The heating element as a whole is arranged in such a manner that the pointed end of the triangle is located a we and in proximity to the forward end of the iron. With this construction, it will be evident that a proportionately large number of turns of resistance wire are located in the region above the 1922. Serial No. 571,802.

forward end of the iron so that a proportionatel large volume of heat is given off by the eating element in this region, thus maintaining the pointed end of the base, which tends to cool rapidly, at the desired operating temperature. The free ends of the heating s iral are electrically connected, as shown in ig. 1, with flat leads 18 and 20, which in the ordinary commercial iron are connected with the terminal plug through set screws 22, the terminal plug being located upon the rear portion of the casing in such a position that a'connection may be readily made. In the resent constructlon, the lead 20 is connected to one terminal 24 of the thermostatic element indicated at 26. Connection is made from the thermostatic element to the terminal plug through an additional lead 28 connected to the thermostatic element by a terminal 30. The heating element as a whole is ordinarily interposed between sheets of mica 32 or similar material and the entire assembly is clam ed to the base member 10 by a weight mem r 40, the weight member being secured in place by through-bolts 42, which pass through the weight member and are ta ped into holes 44 formed in the base. The bolts 42 also serve to retain the usual shell 46 and the'handle 48 in the proper assembled. relation to the base member. According to the resent construction, a thermostatic contro [is embodied in the sadiron for automatically cuttin the heater circuit in and out when re ete mined tern erature limits of the sa iron are reached. 11 order to embody the thermostatic control irr the sadiron, it is only necessary to form a circular recess 50 in the base member, as indicated clearly in the drawings, this recess serving to support a ther-- mostatic assembly, which may be similar in detail to the thermostatic control illustrated in the copending application of Spencer, Serial No. 565,255, filed June 1, 1922. As indicated in this 'application, this control comprises essentially a thermostatic disk 52,

which is supported by a disk 54 of insulating material, the disk 54'being seated in an enlarged portion 56 of the recess 50, the lower portion of the recess receiving the thermostatic disk and associated elements.

As indicated clearly in Figs. 2 and 3. the opening for the thermostatic assembly is formed in the base of the sadiron between the threaded openings 44 and in approximately the center of mass of the base. \Vhen the thermostatic assembly is positioned in the recess, as indicated, and the heating element assembled in 'the proper relation to the base, the terminals 24 and 30 are located between the inclined legs of the heating element and in a convenient position to be connected respectively with the lead 20 and the lead 28. Furthermore, the thermostatic element when located in this position is controlled by a temperature which corresponds to the average temperature of the base as a whole, rather than the temperature of some isolated part of the base, as the pointed end for example. On the other hand, the location of the thermostatic assembly in approximately the central portion of the iron causes the thermostatic control to cut off the heating current of any portion of the base, such as the pointed end, immediately upon reaching the predetermined upper limit of temperature. In order to accommodate the projecting terminals 24 and 30 of the thermostatic assembly, the weight member 40 may be recessed, as indicated at 60. An additional recess or opening may also be provided in the weight member to accommodate the adjusting member 62. By forming and locating the thermostatic assembly in this manner; it will be evident that it may be embodied in a sadiron by merely providing recesses of the proper shape and dimension in the base and weight members, the thermostatic assembly as a whole being held in place by the weight member when the latter is clamped onto the base by the throughbolts 42.

\Vhile it is preferred to employ the specific construction and arrangement of parts shown and described it will be understood that this construction and arran ement is not essential except so far as s eci ed in the claims and may be chang or modified without departing from the broader features of the invention.

The invention having been described, what is claimed-is:

1. A sadiron comprising a pointed base member, a-heater assembly comprising .substantially flat heater strips connected at one end in a substantially triangular formation and superimposed above the base member, a substantially circular thermostatic assembly received in a recessed portion of the base member and spaced rearwardly from the pointed end of the base, a weight member superimposed upon the heater assembly and serving to maintain the thermostatic control within the recess, and means for connecting the weight member to the base.

2. A sadiron comprising a base member having a recess formed therein, a thermostatic assembly received'within the recess and having a disk of insulating material supported in the top portion substantially flush with the surface of the base member, a weight member, a heater element interposed betwen the weight member and the top portion of the base, electrical connection between opposite ends of the heater element and the thermostatic assembly, and means for connecting the base and weight member together. I

3. A sadiron including a base member having an annular recess formed therein surmounted by an enlarged recess forming a shoulder, a thermostatic member having a. base resting in the enlarged recess on the shoulder and an operating portion projecting within the recess in the direction of the under face of the sadiron base, and an upper base section for the iron in the form of a weight member resting oh the thermostatic base to retain it in position in the recess.

4. A sadiron comprising a substantially flat base having a recess formed therein at static assembly received within the recess, a weight member superimposed above the base, a heating element interposed between the weight member and base, and through-bolts extendingthrough theweightmember and into the base-upon opposite sides of the recess in which the thermostatic assembly is received.

5. A sadiron including a basememberhaving an annular recess formed therein surmounted by an enlarged recess forming a shoulder, a thermostatic member having a base resting in the enlarged recess on the shoulder and an operating portion pro'ecting within the recess in the direction 0 the under face of the sadiron base, and an upper base section for the iron in the form of a weight member resting on the thermostat base to retain it in position in the recess, the

.thermostat member having projections extending thereabove and the weight member having recesses receiving the projections in spaced relation thereto.

6. A sadiron including a .base having a shouldered recess formed therein, a thermostat member in the recess having a base portion engaging the shoulder thereof, heater members supported by the base, a weight member surmounting the heater members and a thermostat member, a handle portion for the iron, and fastening members passing .through the handle, weight and base portions for securing the entire iron in assembled relation.

JOHN A. SPENCER.

us the central portion of the base, a thermo- 

